The present invention generally relates a distributed processing system for executing a series of processing operation by using a plurality of computers. More specifically, the present invention is directed to such a distributed processing system that processing operations executed by computers are different from each other, depending upon setting positions of these computers.
Generally speaking, in a distributed processing system for distributing a series of processing operations to be executed by a plurality of computers connected to a network so as to execute these distributed processing operations by these computers, programs executed in the respective computers cooperate with each other, depending upon conditions within this distributed processing system, to perform the processing operations. The above-described conventional method for performing a distributed processing operation by computers is disclosed in, for example, Japanese Patent Laid-open No. 5-347626 (Japanese Patent Publication No. 7-22290). Also, another conventional method for multiplexing the computers so as to achieve high reliability in such a distributed processing system is described in, for instance, Japanese Patent Laid-open No. 9-212209.
On the other hand, in control systems which control controlling subjects, for instance, in a control system for controlling a production line in a production field, the controlling subjects and contents of the processing varies, depending upon places where control apparatuses are installed.
As a result, when the conventional distributed processing system is applied to the above-described control system, since the respective computers employed in the conventional distributed processing system do not manage the processing contents in connection with the setting places of these computers, in such a case that a setting place of one computer is changed and a controlling subject of this computer is changed, a program and a setting value are required to be changed by a programmer and a worker in a production field to change the processing content of the computer.
Recently, since computer-down-sizing trends are specifically realized because of great progress in the microprocessor technology, portable compact devices containing microcomputers, called as xe2x80x9cintelligent devicesxe2x80x9d, are popularized. As a result, processing operations are distributed from a large-scaled computer to a large number of intelligent devices, and furthermore, these intelligent devices (computers) are frequently moved in a production field. Eventually, since programs and setting values (conditions) of these intelligent devices are required to be changed in connection with movement of these intelligent devices, the workloads given to the programmers and the workers in the production fields are rapidly increasing.
An object of the present invention is to provide a distributed processing system and a cooperating method thereof, capable of reducing workloads given to a programmer and a worker in a field in such a case that the structure of this distributed processing system is changed, for example, when a setting place of an intelligent device and the like is moved.
A first distributed processing system, according to the present invention, is a distributed processing system for executing a series of processing operations by a plurality of computers, wherein: a first computer is comprised of a unit for transmitting a message containing an identifier related to a setting place of the computer; and a second computer is comprised of a unit for selectively receiving a message based upon the identifier. The computer in the above distributed processing system corresponds to, for example, a computer for controlling a control device and the like; and also corresponds to an intelligent device constituted by a control device and a computer, for executing a predetermined process operation.
A first cooperating method of a distributed processing system according to the present invention is a cooperating method of a distributed processing system for executing a series of processing operations by a plurality of computers, wherein: a first computer transmits a message containing an identifier related to a setting place of the computer; and a second computer selectively receives a message based upon the identifier.
In the above-described system and method, the message may further contain an identifier related to a device controlled by the above-mentioned computer.
A second distributed processing system according to the present invention is a distributed processing system for executing a series of processing operations by a plurality of computers, wherein: at least one computer among the plurality of computers is comprised of: a unit for seeking another computer when a place where the computer is set is changed, for example, the first-mentioned computer is set at a peripheral portion of the second-mentioned computer; and a unit for reading necessary data from another computer; and also at least one computer changes a setting condition based upon the read data to execute a process operation.
In this case, the above-described a unit for seeking another computer is comprised of a unit for transmitting positional information, for example, via a network to another computer, the positional information indicating a place where the computer is set; and the computer for receiving the positional information is comprised of: a unit for comparing the received positional information with positional information about a place where the own computer is set; and a unit for sending a response in the case that the received positional information is made coincident with the positional information about the place where the own computer is set.
Also, a first intelligent device according to the present invention is an intelligent device used in a distributed processing system for executing a series of processing operations by a plurality of intelligent devices, comprises: a unit for seeking another intelligent device when a place where the own intelligent device is set is changed, for example, the first-mentioned intelligent device being located around the second-mentioned intelligent device; and a unit for reading out necessary data from another intelligent device; wherein: the intelligent device changes a setting condition based upon the read data to execute the processing operation.
In this case, this intelligent device may be further comprised of: positional information managing unit for managing both positional information related to a past setting place and positional information related to a present setting place; and a unit for judging as to whether or not the place where the intelligent device is set is changed with reference to said positional information managing means.
Also, a second cooperating method of a distributed processing system according to the present invention is a cooperating method of a distributed processing system for executing a series of processing operations by a plurality of computers, comprising: a step for seeking another computer, e.g., a computer installed around the computer, when a place where the own computer is set is changed; a step for reading out necessary data from the another computer; and a step for changing a setting condition of the computer whose setting place is changed based upon the read data to execute the process operation. The necessary data corresponds to, for example, a parameter for setting a control device, a parameter for a communication of a computer, and a program executed by a computer.
In this case, the above-mentioned step for seeking another computer is comprised of: a step for registering positional information indicative of a place where a computer is set; a step for transmitting the registered positional information; a step for receiving the transmitted positional information by another computer; a step for comparing the received positional information with positional information indicative of a place where the own computer is set; a step for transmitting a response in such a case that the received positional information is made coincident with the positional information indicative of the place where the own computer is set; and a step for receiving the response by a computer which has firstly transmitted the positional information. Furthermore, when the above-explained positional information is coincident with each other, information related to an apparatus controlled by the own intelligent device may be included in the response to be transmitted.
Also, the second cooperating method may be further comprised of: a step for managing both positional information related to a place where a computer is presently set and positional information related to a place where the computer was set in the past, and for comparing the past positional information with the present positional information, whereby a judgment is made as to whether or not the setting place of the computer is moved. Also, the second cooperating method may be further comprised of a step for confirming a sort of a control device which is controlled by the sought computer.
A second intelligent device according to the present invention is an intelligent device for transmitting data received from a plurality of devices connected to the intelligent device, comprising: a unit for registering a position code with respect to each of the plural devices; a storage unit for storing the data received from the respective devices; a unit for writing data which are received from devices whose registered position codes are identical to each other into the same storage area of the storing means; and a unit for periodically transmitting the data stored in the storage unit to, for example, a network.
Also, a third intelligent device according to the present invention is an intelligent device comprising a computer and an I/O module functioning as an interface for input/output data of a device, wherein: the I/O module is comprised of: a unit for setting a position code; and a unit for transmitting data derived from the device to the computer by applying the set position code to the data; and the computer is comprised of: a storage unit for storing data received from the respective I/O modules; a unit for overwriting the data to which the same position code is applied into the same storage area of the storage unit; and a unit for transmitting the data stored in the storage unit to, for instance, a network.
In this case, the above-explained computer may be furthermore comprised of a table for managing a relationship between the position code and the area for storing the data of the storage unit, and may judge an area for storing the data received from the I/O module based on this table.